Habitat Types

Habitat surveys of the NASA-administered property conducted during fall 2010 identified eight natural terrestrial habitat
types, two aquatic habitat types, and ruderal and developed areas (NASA, 2011). These habitat types are described briefly
in the following text.

Grassland habitat covers 19.2 acres (approximately 4 percent) of the site and often occurs in a mosaic with other habitat
types. Most of the grasslands are characterized by slender oat (Avena barbata), intermixed with other introduced
annual grasses such as ripgut brome (Bromus diandrus), soft brome (Bromus hordeaceus), and fescue (
Vulpia spp). Native grasses including needlegrass (Nassella spp.), littleseed muhly (Muhlenbergia microsperma),
and deergrass (Muhlenbergia rigens) are present in a few areas, but generally provide only minimal cover. Common
herbaceous species include suncup (Camissonia spp.), winecup clarkia (Clarkia purpurea), longbeak stork’s
bill (Erodium botrys), and winter vetch (Vicia villosa).

Coast Live Oak Woodland (13.2 acres)

Coast live oak woodland is distributed widely across the site but only makes up 13.2 acres (approximately 3 percent) of
the NASA-administered property. This habitat is characterized by mature coast live oak (Quercus agrifolia) trees.
The understory generally consists of annual grasses such as ripgut brome and slender oat, with occasional native grasses
including blue wildrye (Elymus glaucus) and California brome (Bromus carinatus). The understory shrub layer
is poorly developed and, where present, generally consists of scattered Pacific poison oak
(Toxicodendron diversilobum).

Coast Live Oak Riparian Forest (9.2 acres)

Coast live oak riparian forest is found along the edges of the seasonal streams on the site. This habitat type covers
9.2 acres (approximately 2 percent) of the NASA-administered property. The composition of this community is generally similar
to the coast live oak woodland habitat described previously, although the understory typically is more diverse in these
areas and includes species such as Douglas’ sagewort (Artemisia douglasiana), creeping snowberry (Symphoricarpos mollis ),
and American black elderberry (Sambucus nigra).

Baccharis Scrub (2.6 acres)

Baccharis scrub is limited, covering only 2.6 total acres (less than 1 percent) of the site. This
community is characterized by generally pure stands of coyotebrush (Baccharis pilularis). In these areas, coyotebrush ranges
from dense cover with a sparse herbaceous layer to more open stands with an understory composed of annual grasses and scattered
forbs.

Southern willow scrub habitat on the NASA-administered property is characterized by arroyo willow (Salix lasiolepis)
intermixed with occasional red willow (Salix laevigata) and narrowleaf willow (Salix exigua). This habitat
type is uncommon on the site, covering only 1 acre (less than 1 percent). Southern willow scrub occurs in localized patches
around scattered ponds and detention basins and along portions of the seasonal drainages within the site.

Aquatic Habitats (0.2 acres)

Aquatic habitats identified on the NASA-administered property include 0.4 acre of open water and 0.2 acre of freshwater
marsh habitat associated with various ponds and detention basins. Freshwater marsh is limited to the outer edges of ponds
and detention basins and is characterized by southern cattail (Typha domingensis).

Sandstone Rock Outcrops (91 acres)

Approximately 91 acres (20 percent) of the NASA-administered property is composed of sandstone outcrops. In many areas,
the outcrops are devoid of vegetation, while in other areas, the rocks are covered with a diverse assemblage of lichens.
In some areas, scattered vascular plants are present. Common plants associated with these rock outcrops include bushy spikemoss
(Selaginella bigelovii), lanceleaf liveforever (Dudleya lanceolata), chalk dudleya (Dudleya pulverulenta),
cliffbrake (Pellaea spp.), orange bush monkey flower (Mimulus aurantiacus), and Santa Susana tarweed (
Deinandra minthornii ).

Ruderal (17 acres)

Ruderal habitat is common around developed areas and areas that have been subject to human disturbance. Ruderal habitats
cover approximately 17 acres (4 percent) of the site. Common species observed in these areas include telegraphweed (
Heterotheca grandiflora ), black mustard (Brassica nigra), Maltese star-thistle (Centaurea melitensis),
silver bird's-foot trefoil (Acmispon argophyllus), stork’s bill (Erodium spp.), and common deerweed.

Developed (58 acres)

Developed areas include paved roads, parking areas, buildings, test structures, and other developments. Approximately
58 acres, or 13 percent, of the NASA-administered property have been developed.

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